1. Field of the Invention
The present invention pertains to methods and systems for the production of liquefied petroleum gases (LPG). Specifically, it pertains to systems and methods for converting natural wellhead gas to LPG.
2. Brief Description of the Prior Art
Gas wells of sufficient volume are normally connected to a gas pipeline for transporting the naltural gas to natural gas markets. While the gas may be separated from hydrocarbon liquids exiting the well and dried, it is basically left in its natural form for such transportation to market.
Some natural gases may be converted to liquified petroleum gas (LPG). The primary advantage of LPG is its ability to be transferred by truck or rail to ultimate points of use not capable of supporting a pipeline. For example, LPG is widely used on farms for heating, crop-drying and dehydration, tobacco-drying, flame cultivation, irrigation pumps, cotton grinning and stationary engine operations. In addition, many farmers use LPG to operate their tractors. Many buses, trucks, forklifts and the like use LPG engines.
Large industrial and manufacturing companies have found LPG to be an answer to heating problems because of its high purity, constant quality and competitive costs as compared with other types of gaseous and liquid fuels. Many small city gas plants utilize LPG. Refineries may use LPG in the manufacture of various grades of gasoline and high-octane motor fuels. LPG is used as basic raw material in the manufacture of many plastic synthetic fibers, synthetic rubber, ect.
In recent years, gas wells which were isolated or otherwise not easily connected to a gas pipeline have been provided with processing units for converting the natural gas to LPG. Thus, the LPG produced thereby can be stored in a tank for transportation by truck or railcar. However, such processing units usually require gas production is excess of 1000 MCFD. This eliminates many wells which produce less than 1000 MCFD. Thus, such wells must be either shut-in or, if produced for their liquid hydrocarbon content, must be flared, wasting the gas produced thereby.